1. Field of the Invention
The present invention relates to a mobile network simulator apparatus, and more particularly, to a mobile network simulator apparatus for checking and testing a communicating operation with a connection destination in a test terminal composed of, for example, a mobile communication terminal.
2. Description of the Related Art
For example, when a mobile communication terminal such as a mobile cellular phone or a personal handy phone (PHS) is newly developed, there is a need for a communication test for checking that the mobile communication terminal can make a communicating operation normally with a connection destination (communication destination).
In the case where such a communication test is executed, a mobile communication terminal to be tested (hereinafter, referred to as test terminal) cannot be connected to a connection destination (communication destination) via an actual base station. Thus, the communicating operation with the connection destination of the test terminal is checked by using a mobile network simulator apparatus having a function similar to the actual base station.
In non-patent document 1 “Anritsu, ELECTRONIC MEASURING INSTRUMENTS, 1998, 6: Radio Communications Test Instruments pp 9–11, 251–253, (MD1620C Signaling Tester) No. '98 GENERAL-E-A-1-(1.00) Printed in USA 1997-11 500QP”, there is disclosed: a mobile network simulator apparatus having a technique of, when such a communication test is executed, sequences indicating procedures and states relating to a test terminal and a connection destination (communication destination) or a measuring instrument having a normal function are detected every time the test is executed, and displaying the sequences on a display device.
In this mobile network simulator apparatus disclosed in non-patent document 1, while a communication line is formed between the test terminal and the connection destination (communication destination) or the measuring instrument, the communication line is formed during communication procedures and communication transition state exchanged with the test terminal between the test terminal and the connection destination (communication destination) or measuring instrument; the communication line is disconnected, and an original state is established. During this period, the communication procedures and communication transition state exchanged between the test terminal and the connection destination (communication destination) or measuring instrument and the mobile network simulator are detected every time, and the relevant sequence is displayed on the display device.
In this manner, personnel who executes testing can visually grasp during which communication procedures and communication transition state the test terminal is established from among a series of communication tests.
Therefore, personnel who executes testing can locate the cause of a failure if the failure occurs in a short time in the communication tests of the test terminal.
However, the mobile network simulator apparatus disclosed in the non-patent document 1 described above still has the following problems which remain unsolved.
In recent years, a mobile communication terminal having a variety of functions has been used as a test terminal. The connection destinations which can be connected to the test terminal include: a general communication telephone terminal; a communication server for transmitting and receiving E-mail or information communication; and a TV telephone (Video call terminal).
Concurrently, a variety of services are provided from a connection destination through a mobile communication terminal which serves as a test terminal. Thus, there is a need for a mobile network simulator apparatus capable of efficiently carrying out a communication test for providing such a variety of services.
In such a mobile network simulator apparatus which executes a communication test, first, a test terminal is connected to the mobile network simulator, and then, connected to a specified connection destination. In this connected state, a test of services provided from the connection destination is carried out, and lastly, the test terminal is disconnected from the connection destination.
In the mobile network simulator apparatus using the technique disclosed in the non-patent document 1 described above, personnel who develops services provided through the test terminal and personnel who executes testing are required to grasp a connection state between the test terminal and the connection destination by analyzing contents of a sequence displayed on the display device.
However, for the personnel who develops services provided through the test terminal and personnel who executes testing, the personnel being unfamiliar with use of the mobile network simulator apparatus, it is difficult to externally grasp the connection state between the test terminal and the connection destination by analyzing the contents of the sequence displayed on the display device. Thus, there is a problem that their workability is likely to be lowered.
In the meantime, one of the characteristics possessed by a mobile communication terminal serving as a test terminal includes reception characteristics (such as receiving sensitivity) when a signal (radio wave) transmitted from a base station is received.
A general technique for measuring the receiving sensitivity of the mobile terminal includes: receiving a signal of a defined signal level outputted from the base station at the mobile terminal; and measuring a reception level of the received signal at the mobile terminal side.
Then, a distance of the mobile terminal from the base station is increased, and a reception level of the received signal at a time point at which the reception level of the received signal at the mobile terminal side has been lowered to an allowable value (limit value) or less is defined as a minimum receiving level of the mobile terminal.
In addition, an example in the case where the receiving sensitivity of the test terminal is measured by using the mobile network simulator apparatus as described above includes: transmitting a test signal which includes predetermined digital data from the mobile network simulator apparatus to the test terminal without changing the distance between the test terminal and the mobile network simulator apparatus (or while making connection via a cable) so as to measure an error bit rate (EBR) of digital data included in the test signal received at the test terminal side.
Then, after measuring a change of the error bit rate (EBR) of the received signal of the test terminal in the case where transmission powers (output levels) of a transmission signal to be transmitted from the mobile network simulator apparatus to the test terminal are sequentially lowered, the transmission power (output level) of the transmission signal at a time point at which the error bit rate (EBR) has exceeded an allowable value (limit value) is defined as a minimum receiving level of the test terminal.
Further, it is also possible to use a technique of sequentially lowering the transmission powers (output levels) of a general communication signal transmitted from the mobile simulator apparatus to the test terminal, and concurrently, checking whether or not a normal response signal is returned from the test terminal to the mobile network simulator apparatus side.
Therefore, in such a mobile network simulator apparatus having a function for carrying out testing of the receiving function (sensitivity) of the test terminal, it is necessary for personnel who executes testing to input the transmission power (output level) of the transmission signal to the test terminal.
In a “display device with a mouse data input function” disclosed in patent document 1 (Jpn. Pat. Appln. KOKAI Publication No. 10-307154), physical switches conventionally provided in equipment are displayed on a display screen of a display device, and a knob in illustration of the displayed switches is moved by a mouse, thereby achieving software switch input.
As described previously, it is essentially necessary to carry out testing of the receiving function (sensitivity) of the test terminal while changing a distance from the base station of the mobile terminal.
Therefore, it is necessary for the personnel who executes testing to input the output level of the transmission signal from the mobile network simulator apparatus to the test terminal while checking a positional relationship between the test terminal and the base station every time by using an input device such as a keyboard. Thus, a testing operation is very complicated.
In actuality, since a plurality of base stations are existed, each base station has a communication area which enables communication with the mobile terminal, thus making it necessary to achieve (simulate) a communication state between the test terminal and each base station in the case where the test terminal is positioned at a portion superimposed with a communication area of another base station which is adjacent to a communication area of a base station in which the test terminal exists as well as a communication state between the test terminal and a base station, the test terminal being positioned in a communication area of the base station.
Therefore, a testing operation by the personnel who executes testing becomes more complicated in order to test more complicated receiving function in the test terminal by using the mobile network simulator apparatus. Thus, there is a problem that their workability is likely to be lowered.